M Sc Dissertation(WII)
Permanent URI for this collectionhttp://192.168.202.180:4000/handle/123456789/3
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Item Ranging, Activity Patterns and Habitat Use of Blackbuck and Nilgai in Velavadar National Park, Gujarat, India(Wildlife Institute of India, Dehradun, 2001) Sahabandhu, H. Dhanushki R.; Chellam, Ravi; Mathur, V.B.I studied the activity patterns, ranging and habitat use of blackbuck (Antelope cervicapra rajputanae) and nilgai (Boselaphus tragocamelus) in Velavadar National Park from November 2000 to April 2001. Scan sampling was used to record blackbuck and nilgai activity patterns. Herds were also followed from sunrise to sunset to study the diurnal movements. Satellite imagery was used for vegetation mapping. Habitat availability and usage of both species were examined by plotting the grazing circuit on the satellite imagery. Activity patterns were found to differ amongst the various social groups, habitats and seasons. Temporal variations in foraging time and resting time were found in all the groups studied. Blackbuck had three foraging peaks and two resting peaks as compared to nilgai, which had two, and one peaks respectively. Diurnal distances were not found to differ in any of the different blackbuck or nilgai groups or between the two species. Differences between blackbuck herds in different seasons and habitats were attributed to the nutritional levels and the spatial dispersion of vegetation. Foraging behaviour decreased in summer supporting results of previous studies that blackbuck reduced foraging due to lower nutrition levels. Male blackbuck was found to forage 67% compared to 58% by females. This difference was attributed to larger body size in males, and the upcoming rutting/lekking season. No difference was found between nilgai males and females, except usage by females was slightly more in high nutritional areas. Female nilgai were found to become more selective in summer, by increasing their foraging time from 43% to 55%. But no difference in habitat usage was found, possibly due to sustenance from Prosopis juliflora pods. Blackbuck were found to spend more time foraging (53%) compared to nilgai (43%). This was due to blackbuck being more selective in the prevailing drought conditions, while nilgai were possibly supplementing their diet with P Juliflora pods. Differences between the two species in temporal allocation of foraging time was found which was ascribed to difference in gut capacity. No seasonal differences were found between the two species, except that nilgai were found to be using high nutrition areas. Nilgai were found to be more selective nutritionally than blackbuck, possibly due to nilgai being an intermediate feeder compared to blackbuck, which are coarse bulk feeders.